Enhancing Ground Fault Protection Coordination Through Effectively Grounding System

Power system protection must be designed to comply with the principles of reliability, selectivity and stability, which can be achieved through proper zoning and coordination. In the context of ground fault protection detection and coordination, appropriate grounding allocation and connection—whether solid or impedance—must be considered throughout the system. Incorrect selection of grounding location or connection may lead to undesirable disturbances and cascading failure. This paper presents a corrective design for ground fault protection detection and coordination in a 34.5 kV power system network that has experienced several instances of ground fault protection misoperation. First, the system’s grounding is evaluated using the zero sequence (ZS) network. Evaluation of the corrected grounding design involved applying three case studies to observe ground fault detection. Then, the IEEE 142-2007 standard is used to the optimal location and connection for grounding, ensuring an effective grounding system. Simulations conducted using power system analysis software verify the design’s ability to address misoperation issues and enhance fault detection and system stability.